Aviation officials have confirmed that two people were aboard the plane that went down about a mile offshore Pier Avenue in Oceano on Tuesday and that the plane took off from Santa Maria Airport.

The San Luis Obispo County Sheriff’s Office previously identified the pilot as David Brian Casey, 63, of Friday Harbor, Wash.

Officials said Friday they don’t yet know the identity of the second person in the plane.

The Morrisey 2150 departed from Santa Maria Airport at approximately 1:30 p.m. Tuesday, said Jim Struhsaker, spokesman for the National Transportation Safety Board. The aircraft, a small, fixed-wing, single-engine plane, was registered to Casey.

Since the crash, the sheriff’s Dive Team and Marine Enforcement Unit have been searching for the plane and any remains. The search will continue through the weekend, said Tony Cipolla, spokesman for the Sheriff’s Office.